Flaps to aid climbing - truth or fiction

[Tom Baker]

I only use 15 flaps for take off to a safe altitude before changing to zero flaps and for landings.

 

My whole point is, that when the wheels leave the ground until you reach your safe altitude will happen in a shorter period of time with 0° flaps. If you are worried about where you are in relation to the end of the runway or an obstacle then use 15° flaps. To think you are getting to a safe altitude with 15° flaps faster based on where you are in relation to the runway is an illusion based on position not time.

[Tom Baker]

BTW, I use 15° flaps for take off because I like that the airplane comes off the ground at a slower speed and feels better compared to 0° flaps. My normal procedure is 15° flaps, rotate at 45kts indicated, then climb at 62kts. I also wait until a safe altitude to remove the flaps. 

[Roger Lee]

Hi Tom,

 

You're partially right. I don't care about time, but position. If at the end of the runway I'm higher with 15 flaps over zero  then that's what I prefer. Time doesn't figure into for me. I'll have some more numbers this week with exact distances.

 

I will say I do like Newton's law pushing me skyward.  

[FlyingMonkey]

BTW, I use 15° flaps for take off because I like that the airplane comes off the ground at a slower speed and feels better compared to 0° flaps. My normal procedure is 15° flaps, rotate at 45kts indicated, then climb at 62kts. I also wait until a safe altitude to remove the flaps. 

 

I do exactly the same.  15° flaps, rotate 45kt, climb ~60kt.  I go to 0° flaps at 500agl, and -6° once speed gets above 70kt, which is usually only a few seconds.

 

BTW, something else to consider:  Even if you can climb faster at 0° flaps than at 15° flaps, is that desirable?  At 0° you will be traveling faster.  At one minute into the flight, you might be at 600ft AGL at zero flaps, but 1/4 - 1/2 mile from the airport.  At 15° flaps you might only be at 500ft AGL, but still over the runway and in a good landing configuration.  I know which I'd prefer if the engine quits.

[Tom Baker]

Hi Tom,

 

You're partially right. I don't care about time, but position. If at the end of the runway I'm higher with 15 flaps over zero  then that's what I prefer. Time doesn't figure into for me. I'll have some more numbers this week with exact distances.

 

 

 

If that is what you want that is fine. I think most pilots would prefer to get to a safe altitude in the  quickest time possible.

[Tom Baker]

I do exactly the same.  15° flaps, rotate 45kt, climb ~60kt.  I go to 0° flaps at 500agl, and -6° once speed gets above 70kt, which is usually only a few seconds.

 

BTW, something else to consider:  Even if you can climb faster at 0° flaps than at 15° flaps, is that desirable?  At 0° you will be traveling faster.  At one minute into the flight, you might be at 600ft AGL at zero flaps, but 1/4 - 1/2 mile from the airport.  At 15° flaps you might only be at 500ft AGL, but still over the runway and in a good landing configuration.  I know which I'd prefer if the engine quits.

 

Andy, with close to 10,000 hours of flight time it is something I have considered. I have had a partial power failure in a somewhat unfamiliar airplane just as I was crossing the departure end of the runway. There are lots of factors, but based on experience I would choose the altitude. If you are over the departure end of the runway and haven't made a turn and your engine quits you are in a bad spot. In most cases you are to high to make a 180 and land back on the runway and to low to make the 360 back to the runway.

[Ed Cesnalis]

Rotation speed is always unknown to me but my plane knows what it is.  Its always a little different. a slight amount of backpressure on take-off roll will allow your CT to take off as soon as flying speed is reached (trim must be set without too much nose down).  This technique is a mistake in a crosswind that will challenge your directional  control as you get light.

 

In the high west airports that have long runways I use a technique with a faster initial climb.

• Set trim nose down (not too much where holding the nose up doesn't work.)
• As the mains begin to rise relax the back pressure and simultaneously lower the nose.
• Keep nose low and remain in ground effect or at least close until you have reached a speed > Vx.
• Now in an enhanced energy state begin your initial climb.

On my last BFR I told the CFI that I was going to climb with my nose low and when we departed he agreed that we were departing like a helicopter.  Truth is the pitch attitude in the CT is hard to interpret and it looks nose low when its at a very slight positive angle.

[Ed Cesnalis]

Andy, with close to 10,000 hours of flight time it is something I have considered. I have had a partial power failure in a somewhat unfamiliar airplane just as I was crossing the departure end of the runway. There are lots of factors, but based on experience I would choose the altitude. If you are over the departure end of the runway and haven't made a turn and your engine quits you are in a bad spot. In most cases you are to high to make a 180 and land back on the runway and to low to make the 360 back to the runway.

 

 

You can't actually be 'too high' to return on a 180 tear drop but you can fail to recognize that you are too close and need to extend your upwind or elongate your tear drop.

[Roger Lee]

I would prefer closer to the runway at 500' than farther out and possibly no chance to make a return or 180 back to land.

500' straight out at zero flaps will put me in the bushes if I have an emergency or engine out. 500' right off the end of the runway puts gives me an easy 180 right back on the runway.

 

Hi Ed,

 

My plane wants to start flying right around 40-42, but I keep it on the ground for at least 5 more knots. 40 is hanging at stall and is squirrelly and too nose high for me especially in winds. I'm a minimum of 45-50 before I rotate. Like stall landings I prefer a speed buffer for unforeseen circumstances and they do happen to many or so many people wouldn't have smashed gear. It could be the plane's fault, your fault or weather, but it happens. That extra 5 knots gives me an extra split second to level if the engine quits at 4-6 ft off the deck. A stall speed lift off at 40-42 just drops me if I would have an engine quit and then factor in human reaction time.

 

 

 

Here is my exact argument on 15 flaps vs zero flaps and why many of these debates have no real solution between individuals. 

The issue with trying to pin something down is all the variables between plane and pilot.

 

Landing at stall or not, which way to do this or that.

 

We all have different flying skill sets. Many of us were taught different and come from different backgrounds. 

 

Bottom line is they all work and have been for a hundred years and they are all within the scope of each aircraft's performance envelope and many are very similar with just slight variances.

 

This is one reason I rarely get into these types of topics. Too many variances and they are all okay. I got into this one to show how many variances there are and you all proved they all work and are acceptable practices.

 

Most of these things like zero vs 15 takeoffs is just a personal choice and tailored to the specific circumstance you have at your airport or place of departure or landing.

 

They're all normal we just have different styles and likes and dislikes. personal choices most times are within the scope of what you are trying to accomplish so debating who's is better many times can be futile at best, but they are both right.

 

Chevy's vs Ford's.

[Roger Lee]

The key for me with my flying skills is flexibility and knowing when to be flexible and how to be flexible. Hardcore one way pilots may have issues under certain circumstances.

Flying is all about being calm and relaxed even when it hits the fan. You can take the time to whimper after you get back down.

[Ed Cesnalis]

I wasn't arguing 15 vs zero, I always use 15.  I was pointing out that in a high shear environment it can be a good idea to keep your nose low when climbing and even accelerate in ground effect before you initiate your climb.

 

We are both looking to enhance safety on departure.  I used to climb away at what looked like a 45* angle in my Challenger and lots of people reacted with "what if you stall in that attitude near the ground?"  I see that as a pretty serious question in the CT because I will fly it in the afternoons If I need to go somewhere.

[Tom Baker]

Rotation speed is always unknown to me but my plane knows what it is.  Its always a little different. a slight amount of backpressure on take-off roll will allow your CT to take off as soon as flying speed is reached (trim must be set without too much nose down).  This technique is a mistake in a crosswind that will challenge your directional  control as you get light.

 

In the high west airports that have long runways I use a technique with a faster initial climb.

• Set trim nose down (not too much where holding the nose up doesn't work.)
• As the mains begin to rise relax the back pressure and simultaneously lower the nose.
• Keep nose low and remain in ground effect or at least close until you have reached a speed > Vx.
• Now in an enhanced energy state begin your initial climb.

On my last BFR I told the CFI that I was going to climb with my nose low and when we departed he agreed that we were departing like a helicopter.  Truth is the pitch attitude in the CT is hard to interpret and it looks nose low when its at a very slight positive angle.

 

That seems to be one of the differences between the CTSW and the CTLS. The LS needs the nose up for climb, where the SW will climb in what seems to be a flat attitude.

[Tom Baker]

You can't actually be 'too high' to return on a 180 tear drop but you can fail to recognize that you are too close and need to extend your upwind or elongate your tear drop.

 

I agree, but it requires a higher skill set.

[Roger Lee]

Hi ED,

 

"I wasn't arguing 15 vs zero, I always use 15.  I was pointing out that in a high shear environment it can be a good idea to keep your nose low when climbing and even accelerate in ground effect before you initiate your climb."

 

I fully agree.

 

All part of identifying your specific flight parameters and being flexible enough to see where and how to put the odds in your favor in case there is an emergency.

You and I came from the old Ultralight backgrounds. Dealing with emergencies was second nature and setting yourself up for that emergency was foremost in your mind and not letting yourself get behind the eightball. Playing catchup in an emergency or stall near the ground is not a fun place that anyone wants or should be in. Recognising that before it happens and setting yourself up in advance is good forward thinking. Not everyday day in life or flying will be perfect.

[FastEddieB]

 

We are both looking to enhance safety on departure.  I used to climb away at what looked like a 45* angle in my Challenger and lots of people reacted with "what if you stall in that attitude near the ground?"  I see that as a pretty serious question in the CT because I will fly it in the afternoons If I need to go somewhere.

One important consideration:

 

There is a time and a place for a Vx climb. But at that slow speed, an abrupt engine failure would have to be dealt with very quickly and very positively.

 

We all imagine we could react almost immediately to something like this. In real life, there's often about a 3 second "deer in the headlights" period of disbelief before doing anything. In that few seconds, one can be near or even at stall speed. Any sort of a turn at that point can easily result in the classic stall/spin scenario that's killed so many.

 

That's why, as soon as clear of obstacles, a transition to a Vy or even a cruise climb speed is a very good idea.

[Tom Baker]

 

Most of these things like zero vs 15 takeoffs is just a personal choice and tailored to the specific circumstance you have at your airport or place of departure or landing.

 

They're all normal we just have different styles and likes and dislikes. personal choices most times are within the scope of what you are trying to accomplish so debating who's is better many times can be futile at best, but they are both right.

 

Chevy's vs Ford's.

 

Roger, I wouldn't dream argue about preferences. You can take off or land however you want. What I an discussing or arguing if you will, is the fact that earlier in this thread you said the airplane will climb faster with 15° flaps. You then tried to use the airplane being higher at the end of the runway as proof. Faster is an element of time, not position in relationship to the runway. If your goal is to get to a safe altitude as quickly as possible you are using the wrong unit of measure.

[Ed Cesnalis]

as soon as clear of obstacles, a transition to a Vy or even a cruise climb speed is a very good idea.

 

    ^this

[Tom Baker]

 

That's why, as soon as clear of obstacles, a transition to a Vy or even a cruise climb speed is a very good idea.

 

I teach when clear of obstacles to use Vy until you are out of the pattern, then transition to cruise climb. Use best rate until you are at a safe altitude.

[ralarcon]

I do exactly the same.  15° flaps, rotate 45kt, climb ~60kt.  I go to 0° flaps at 500agl, and -6° once speed gets above 70kt, which is usually only a few seconds.

 

BTW, something else to consider:  Even if you can climb faster at 0° flaps than at 15° flaps, is that desirable?  At 0° you will be traveling faster.  At one minute into the flight, you might be at 600ft AGL at zero flaps, but 1/4 - 1/2 mile from the airport.  At 15° flaps you might only be at 500ft AGL, but still over the runway and in a good landing configuration.  I know which I'd prefer if the engine quits.

Most of the airports I frequent have, rather, long runways. At KLAL. where I'm based I use 0 flaps, climb at 70 knots , before the end of the runway I'm at 400 to 500 feet AGL. Then switch to -6 flaps and continue climbing. do this 99% of the time on most airports. Short strips , I use flaps 15 , climb at 65 knots, then switch to 0 at 600 AGL, get a significant droop, have to warn passengers, and then progress through 0 to -6.

 

Cheers

[Tom Baker]

Most of the airports I frequent have, rather, long runways. At KLAL. where I'm based I use 0 flaps, climb at 70 knots , before the end of the runway I'm at 400 to 500 feet AGL. Then switch to -6 flaps and continue climbing. do this 99% of the time on most airports. Short strips , I use flaps 15 , climb at 65 knots, then switch to 0 at 600 AGL, get a significant droop, have to warn passengers, and then progress through 0 to -6.

 

Cheers

 

With practice you can catch that "droop" and make it where it is not noticeable. I know students are getting it in the CT when 2 things happen in the pattern. 1. when you go from 15° to 0° flaps you don't feel the sinking feeling. 2. When reducing power abeam the numbers the nose doesn't swing to the right.

[Ed Cesnalis]

When abeam the numbers both 'closing the throttle' as well as deploying 15* flaps mess with the nose.  I do both at the same time while I control the nose, easier than 2 events.

[ralarcon]

With practice you can catch that "droop" and make it where it is not noticeable. I know students are getting it in the CT when 2 things happen in the pattern. 1. when you go from 15° to 0° flaps you don't feel the sinking feeling. 2. When reducing power abeam the numbers the nose doesn't swing to the right.

What do you do, lower the nose ?

 

Cheers

[ralarcon]

When abeam the numbers both 'closing the throttle' as well as deploying 15* flaps mess with the nose.  I do both at the same time while I control the nose, easier than 2 event

 

Don't have any problems on the pattern just the noticeable sinking when , on departure, switch from  15 to 0 flaps.

 

Cheers

[Tom Baker]

What do you do, lower the nose ?

 

Cheers

 

This is for the LS not the SW. I don't remember it being a problem for the SW.

 

First I don't change trim prior to take off. After take off I hold forward pressure on the stick, until I remove the flaps. During the process I change from forward pressure to neutral or slight back pressure. If you make the transition the same time as the flaps are moving it will feel seamless.

[ralarcon]

This is for the LS not the SW. I don't remember it being a problem for the SW.

 

First I don't change trim prior to take off. After take off I hold forward pressure on the stick, until I remove the flaps. During the process I change from forward pressure to neutral or slight back pressure. If you make the transition the same time as the flaps are moving it will feel seamless.

Ok, I'll try it .

 

Thanks